56) Notam cu x elevii scolii.
36/100 * x = 900
36x=900*100
x=90000/36
x= 2500 de elevi
57) Dupa prima reducere : x- 10/100 * x = x- x/10 = 9x/10
Dupa a doua reducere: 9x/10 - 10/100 * 9x/10 = 1968,3
9x/10 - 9x/100 = 1968,3
90x-9x=196830
81x=196830
x=2430 lei
58) Dupa prima crestere: x+ 15/100 * x = x + 3x/20 = 23x/20
Dupa a doua crestere: 23x/20 + 10/100* 23x/20 = 12144
23x/20 + 23x/200 = 12144
230x + 23 x = 2428800
253 x = 2428800
x = 9600 de euro